In article ,
Dave Cornwell writes:
I defy anybody to claim they know what is going to happen in a weeks
time. The divergence of the output is such that there is almost 17 degC
difference between highest and lowest GFS ensemble members (850 hPa)
for the whole period after the 20th. I'm reasonably confident that the
maximum temperature on Christmas Day will be between -2C and 10C.
Dave

The 00Z shows a similar spread.

Incidentally, the scenario the models are showing of a low moving south
from Spitzbergen later this week (I still stick to the old convention
that Sunday is the first rather than last day of the week) reminds me a
lot of last February.
--
John Hall
"I look upon it, that he who does not mind his belly,
will hardly mind anything else."
Dr Samuel Johnson (1709-84)